Cellulose derivative compositions



cellulose derivatives.

' compositions containing cellulose derivatives 7 I I Cellulose acetatePatented Sept. 29, 1931 UNITED STATES: PAT

ENT oer-Ice wanna :s. LAWSON, or wmxme'roir, DELAWARE, ASSIGNOB To B."1. in: rear DE.

mom a comm, wm

name".

This" invention relates to the art of soft- I eners, and moreparticularly to softeners for It is an object of this invention toproduce which willform films of flexibility. h

It is also an object of this invention toprohaving a highdegree m videnew and useful coating compositions.

I have found that acetals in which the al cohol constituents containmore than one ether group 'andhaving relatively low 'vapor I 4 pressuresare compatible with various cellus 15 km derivatives and that they makeexcellent softeners or plasticizers for-such materi and forcelluloseacetate infparticular.

Examples of compositions embodying my invention are set forth below byway of illustration. and not as a limitation.

Emplelram 1:, weight Acetal of the monoethyl ether of diethyl- Solvent:acetone, 60%; methyl ether. of

ethylene glycol, 30%; diacetone alcohol go This yields films ofexceptionalsoftness,

flexibility, andclarity. Tests extendin over a period of three monthsshowed nochange I in these properties; j I vEa: m 2 g pk Parteby weightPyroxylin Acetal-of the monoethyl ether of diethylene glycol Solvent:ethyl acetate,"80%; butyl acetate,20% 80.5 The film secured byevaporation of this solution was clear and tough.

Ewmpleo Parts by weight Acetal of the butyl ether of diethylen ycol-QSolvent: ethyl acetate, 80%; butyl aceso tate, so. 5

v Acetal of the monoeth of the etliy 3 has the following described coCellulose acetate or wrmmwemou, nmwann, a coarommox or nmm mosa nmvarmcomer-none Application am September 1:, ma. min xol seg m'za.

produces a clear, tough and flexible Example 4 V Benzyl cellulose ylethe Parts by weight 10 r of diethylene glycol Solvent: toluene, 50%;butyl alcohol,

50%- 88 This composition gave a vsatisfactory film which was bothclearand flexible.

v Example 5" Ethylcellulose n Parts by weight h 10 Acetal of themonoethyl ether of die-- ethylene" glycol.; i 3

Solvent: benzene, 50% 5 toluene, 50% 87. The results were similar-tothweobtained with other cellulose derivatives. 7o

' Ewample 6 a A sprayinglacquer conta' the acetal 'l ether of diethyleneycol which ound to give tough, a erent films,

mposition:

Parts by weight has been Aceta'l of the monoeth lene glyc emi resin 7Solvent: acetone, 17%; denatured alco-' hol, 9%; ethyl acetate, 12%;acetone oils, 20%; toluene 20; methylether of ethylene glycol, 22% 179The acetal of the monoethyl ether of diethylene glycol referredto abovehas the formula.

yl ether of diethy- 6 011,011 oomomocnzcmoomom)i and a boiling point of14014 5 C. under apressure of 14 mm. This may be prepared 1n variousways as indicated in the -co- I pending application filed of even dateherewith by Julius A. Nieuwland, Serial No.

305,867, but the preferred method is as 1501- lows: r

A 20% solution of fluoboric acid in ethyl alcohol weighing 10 grams iswarmed with .two grams of mercuric oxide until a portion of the mercuricoxide has gone into solution.

' of plasticizer in the film. thus giving To this catalyst mixture isthen added 200 grams of the ethyl ether of diethylene glycol, andacetylene is passed in until an increase in weight of 20 grams occurs,corresponding to the absorption of one-half gram mole acetylene per grammole of the ethyl ether of diethylene glycol. When the rate of thereaction decreases, additional mercuric oxide is added in two gramportions, not more than 10 to 12 grams being required for a charge ofthis size. On the completion of the reaction the product is neutralizedwith saturated potassium carbonate solution, dried with anhydrouspotassium carbonate, and distilled yielding the acetal in a high stateof purity.

Instead of using the acetal of the monoethyl ether of diethylene glycol,its homologs, such as the acetals of the methyl, propyl or butyl ethersof diethylene glycol, may be employed and may be made in a'similarmanner.

I prefer, however, to use the acetal of the monoethyl etherof diethyleneglycol on account of its low cost, satisfactory compatibilities withvarious cellulose derivatives, tendency to favor adhesion of film, andretention 1ncreased duration of flexibility.

As many apparently widely different embodiments of this invention may bemade without departing from the spirit and scope thereof, it is to beunderstood that I do not limit myself to the specific embodimentsthereof except as defined in the appended patent claims.

I claim:

1. A composition comprising a cellulose derivative and, as a softenertherefor, an acetal of an alkyl ether of diethylene glycol.-

2. A composition comprising-a cellulose derivative and, as asoftenertherefor, the acetal of the monoethyl ether of diethylene glycol.

3. The composition of claim 2, in which the cellulose derivative iscellulose acetate.

4. A composition comprising a cellulose derivative. an acetalo'f an"alkyl ether of diethylene glycol, and'asolvent.

5. The composition of claim 4, in which the cellulose derivative iscellulose acetate.

6. A composition comprising 12 parts by weight ofv a cellulosederivative, 6 parts by weight of an acetal of an alkyl ether ofdiethylene glycol, and a solvent.

7. The composition of claim 6, in which the cellulose derivative iscellulose acetate.

8. A composition comprising 12 parts by weight of a cellulosederivative, 6- parts by weight of the acetal of the monoethyl ether ofdiethylene glycol, and a solvent.

9. The composition of claim 8, in which the cellulose derivative iscellulose acetate.

In testimony whereof, I aflix my signature.

WALTER E. LAWSON.

